I think because fuji have their Fuji Europe regional setup, providing Fuji Europe order sufficent quantity from Japan they can still do it. I guess there isn't enough demand in the US for Fujifilm USA to order large enough quantities which is the reason I was told by Fuji UK that some of their products aren't supplied to some regions.
The kit can be had for £110.46 in the UK which is enough for around 40 35mm films. Not cheap even here. I hate to think what shipping to US would be.
But you can buy the individual chemicals in the US but only in larger quantities by the look of it.
It would be cheaper for me to send them to a lab. I pay 2.38 to have my slide film (135/120) developed by Fuji themselves (I think their plant is in Germany).